This range of Reverb Tank is designed for deep and smooth reverb, no fluttering but wide frequency response with airy top end instantly inspiring to enjoy guitar playing. The rock solid mechanical design assures a very dependable and consistent quality performance exceeding any expectation. The Type 4 provides the signature sound that helped make the Fender Reverb Amps famous since the early 1960s. It uses four counter wound and coupled springs delivering superior mechanical performance.